Fatal Calf Pneumonia Outbreaks in Italian Dairy Herds Involving Mycoplasma bovis and Other Agents of BRD Complex

Abstract

Mycoplasma bovis is increasingly recognized worldwide as an important cause of disease with major welfare and production impairments on cattle rearing. Although it was detected in veal calves and beef cattle, little is known on the infection impact and on its temporal morbidity pattern in Italian dairy herds. Thus, this study aimed to investigate the involvement of M. bovis on fatal calf pneumonia outbreaks that occurred during 2009–2019 in 64 Italian dairy farms. Furthermore, a deeper diagnostic workup of concurrent infection with other viral and bacterial respiratory pathogens was assessed. Out of the investigated fatal pneumonia cases, M. bovis was frequently detected (animal prevalence, 16.16%; 95%CI, 11.82–21.33; herd prevalence, 26.56; 95%CI, 16.29–39.08) either as the single agent of the disease in more than half of the positive samples (20/37) or in concurrent infections with Histophilus somni (9/37, 24.3%), Mannheimia haemolytica (6/37, 16.621%), Trueperella pyogenes (1/37, 2.70%), Pasteurella multocida (1/37, 2.70%), bovine respiratory syncytial virus (5/37, 13.51%), and bovine viral diarrhea virus (2/37, 5.55%). Based on time-series analysis, M. bovis was recorded in the area since 2009 with outbreaks displaying a clear morbidity seasonal pattern with peaks in April (43.21%) and in September (13.51%). This might be due to the stressing conditions during spring and late summer periods. Results of this study highlight that M. bovis infection warrants consideration, and control measures are needed given its involvement in lethal pneumonia outbreaks in dairy herds from an extended area.

The Prevalence, Coexistence, and Correlations between Seven Pathogens Detected by a PCR Method from South-Western Poland Dairy Cattle Suffering from Bovine Respiratory Disease

“…The prevalence of P. multocida varies widely ranging from a few percent to over eighty [ 5 , 8 , 14 , 15 , 16 , 17 , 19 , 20 , 28 , 32 , 35 , 36 , 37 , 38 ]. Similar to our results, Paller et al noted that the highest prevalence occurred for P. multocida (58.64%) [ 32 ].…”

“…However, their study was conducted on a smaller group, as well as a different region of Poland [ 44 ]. The prevalence of M. bovis shown by researchers from other regions of the world varies even more: from a few percent to over eighty [ 8 , 15 , 16 , 19 , 28 , 32 , 33 , 35 ].…”

“…Pathogens noted in the course of BRD include: Pasteurella multocida ( P. multocida ), Mannheimia haemolytica ( M. haemolytica ), Mycoplasma bovis ( M. bovis ), Histophilus somni (H. somni), bovine parainfluenza virus type 3 (BPIV-3), bovine respiratory syncytial virus (BRSV), bovine coronavirus (BcoV), bovine viral diarrhea virus (BVDV), bovine herpes virus type 1 (BHV-1), bovine adenovirus (BadV), and influenza D virus (IDV). Stress or viral infections create a basis for opportunistic bacteria to multiply, which contributes to clinical symptoms [ 2 , 5 , 7 , 8 , 9 , 10 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ].…”

Efficiency‐corrected PCR quantification for identification of prevalence and load of respiratory disease‐causing agents in feedlot cattle

“…M. bovis is a slow growing, host-specific commensal that has been implicated in a number of bovine diseases including mastitis, arthritis, pneumonia, and in some reproductive losses, 31 and particularly in the development of lung lesions in cattle. 32 Whilst it is accepted that M. bovis can be causal for respiratory disease outbreaks in cattle, particularly when present in combination with other BRDcausing microorganisms, 33,34 this study is the first to identify that cattle entering the Australian feedlot system at induction are not carrying detectable levels of M. bovis in their upper respiratory tract compared to cattle located in the hospital pen at the same location. Our findings are similar to those of a Canadian study that reported low M. bovis prevalence in animals at induction (1.7%) which increased over time in the feedlot (≤15 days -72.2%, 55 days 85.7%).…”

Genomic and Transcriptomic Analysis of Bovine Pasteurella multocida Serogroup A Strain Reveals Insights Into Virulence Attenuation

“…Among these bacteria, Pasteurella multocida ( P. multocida ), a pathogenic gram-negative bacterium, has been divided into three subspecies, five capsular serogroups, and 16 serotypes. P. multocida serogroup A is commonly isolated from both enzootic calf pneumonia of young dairy calves and shipping fever of weaned and stressed beef cattle ( 4 ). In Belgium between 2016 and 2018, analysis of the cattle samples from 128 BRD outbreaks found P.multocida with a detection rate of 89.1% ( 5 ).…”